A Mission Before Dying
by Maddy77
Summary: "I have...someone to visit, a favor to ask, and an ultimatum to make." The Doctor has Winchester business to finish before the end comes. Spoilers for SPN S4, DW through "The End of Time".
1. Someone to Visit

Author's Note: This is a direct continuation from "What Power", and is also a sequel to "The Shadow Proclamation". So I'd very much recommend reading both of those before reading this one.

This is a short, three-part prelude to the next big multi-chapter story in this 'verse. Let me know what you think!

* * *

**_Someone to Visit_**

Another cheap motel in another town. As usual.

The blue phone box in the parking lot was doing its best to blend in, but the man who stepped out of it made no such effort. So little so that in the parking lot, two young men enacting a drug deal and a man soliciting sex from a prostitute decided that the parking lot wasn't necessary such a good place to be anymore and postponed their various affairs.

The man was glowing faintly, golden with brilliant white motes in the aura.

The Doctor was dying.

Well. Inasmuch as the Doctor could die. The radiation was killing him, and any moment now, his body as it currently existed would begin to shut down for the last time. He would regenerate, yes. But this body, this Doctor, would die.

And this Doctor, in this body, wanted to find out what had happened to Samuel.

So he'd come here, to 2008, to find out.

It wasn't that he didn't know. Not precisely. He suspected, and he was clever, so his suspicions usually ended up being the truth. But he wanted to believe in Samuel a little more than that. He wanted to be wrong—something he so rarely wanted to be.

Though Samuel didn't know yet, they'd had so many adventures together. Samuel and his brother had become as close as Companions to the Doctor, and the Doctor could really _see_ them. And he knew that something had happened, between the affair with the Shadow Proclamation and Dean's return from Hell. He'd checked in on Samuel a few times during Dean's ordeal, but he'd never managed to find him doing anything more untoward than excessive drinking.

Drinking wouldn't have opened his mind up like it had been opened.

The Doctor could hear the gaping, screaming space of it from the parking lot. The neurological defect that made the boy's brain crave the creation of new synapses was being triggered by something, and there were few things that could activate it. He had to know. Before the end, he had to know.

He stepped in front of the window into the room that Samuel had rented for himself, and peered in.

Ah.

The understanding came like a blow to the stomach. The Doctor looked away quickly, not to give Samuel privacy, but because he truly could not bear to see it. To see Samuel's lips stained with the creature's blood, to see the desperation, the want, the _need_ in his addict's eyes as he pressed her arm to his mouth.

A hard knot of anger formed in his chest. He'd told him. He'd warned him _specifically_ that the introduction of extraterrestrial substances into his system could trigger the Time Lord biology of his brain and leave him open to attack. He'd even used demon blood as an example. And yet.

The fists that his hands had clenched into relaxed, and he passed them across his face. His body was beginning to ache. He'd had to know. He knew. He didn't have the time for self-indulgent emotions. He couldn't do anything to stop Samuel—it would be crossing his own timeline. It would create a paradox. He couldn't do that. Wouldn't do it.

Especially, a small, grief-filled voice in the back of his mind whispered, not to the Winchesters. Not after everything.

It was a testament to how long he'd lingered, and how far gone he was, that he didn't hear Samuel come to the door. That he barely heard the door open. He looked up with effort as Samuel whispered, "Doctor?"

The Doctor smiled wearily. "Samuel."

"Doctor, what's wrong?" Samuel asked, sounding panicked. The Doctor considered briefly how he must look. Pale, surely. Exhausted.

"It's not important, Samuel," the Doctor said. He glanced over the boy's shoulder, where the demon hung back by the bed, watching him with wide eyes.

Samuel frowned, and turned. He froze when he saw the demon, realized that the Doctor knew. He turned back with an agonized expression on his face. "Doctor—"

The Doctor shook his head, his eyes closed. "Don't," he said. "You don't—it's your life, Samuel. And I'm in the wrong order."

Samuel paused, then furrowed his brow. "I don't...know what that means, Doctor. Look, just come in, we'll figure this out." He put a hand on the Doctor's arm, intending to guide him into the hotel room, to fix what was wrong. To do his damnedest. It was the Winchester way.

The Doctor put his hand on top of Samuel's, stopping him. Samuel looked at him, confused, helpless. "It's all right," the Doctor said softly. "Samuel, it's all right."

"There's something wrong with you," Samuel said, breathlessly. "Doctor. _Please_. Come in. Let me help you. I'll call Bobby. Whatever's going on, we'll make it right."

When the Doctor didn't move, Samuel's voice dropped further, until he was barely audible as he breathed, "Doctor, I can't lose anyone else." He swallowed hard, and glared down at the ground. "I just can't."

The Doctor watched as Samuel's eyes reddened, as he fought tears. "You're not," he said. Sam looked back up instantly. "You're not losing me, Samuel. You'll see me again _very_ soon. I'll be dropping by in a few weeks. I was just...coming to check on you."

"Why do you look like this?" Samuel asked. He was never one to let something go easily. "You're...glowing. You look really sick, Doctor. And you feel...wrong. In my head."

The Doctor raised an eyebrow at him instead of yelling.

At least Samuel looked embarrassed.

"I have to be going," the Doctor said. "But...don't mention this, the next time you see me. Just pretend it didn't happen."

"Why?" Samuel asked.

The Doctor decided to ignore the question, instead gripping Samuel's shoulder with a strength he hadn't been positive he still possessed. "Please be careful," he said. "Take care of yourself. You deserve better."

"Yeah," Samuel laughed softly. "Let's not talk about the things I deserve."

"You," the Doctor said fondly, "are impossible." He let his hand fall from Samuel's shoulder, and he pressed his temples. Samuel was moving to catch him before he even swayed, grasping his shoulders to keep him from falling, and the Doctor looked up at the young man as he recovered. "You shouldn't be in there," he scolded. "It's a mess."

Samuel shrugged, not looking repentant. "Can't make out much in there anyway," he said. "Too many thoughts for me to sort out, Doctor."

"You're telling me," the Doctor retorted. He straightened with Samuel's help, and looked the Hunter in the eyes.

He wanted to say something that could comfort Samuel in the hard days to come. He wanted to say something that could soften the edge of his pain, something that could give him what he sought at the bottom of so many bottles, inside that creature's veins.

It was not long ago, not at all, that the Time Lord Victorious might have said something—warned Samuel of what would happen, were he to continue down this path. Changed his future. Changed the future for all of them.

But he'd learned his lesson with Adelaide.

So he put his hand on Samuel's arm and said, "Trust yourself, Samuel. You're better than you know."

He turned to limp off, and stopped when he heard Samuel's voice behind him. "Doctor!" He didn't turn, but waited. Samuel's voice came again, more hesitant: "I'll...see you around."

He winced. _I've never seen two people so alike._ So he gave Samuel the same response he'd given his brother. "Yes. You will."

He didn't, couldn't, turn back to look one last time at the wonderful, brilliant, brave boy whose life his blood had ruined. Who held no grudges. He limped back to the TARDIS, closed the door behind him, and leaned heavily on it.

There was not time to rest, though.

Before it was over, he had to see a transdimensional caeloform wavelength about a boy.


	2. An Ultimatum to Make

Author's Note: I know the Doctor said "someone to visit, a favor to ask, and an ultimatum to make", but it works better as a lead-in to the next story if the favor is last.

Thanks for sharing your thoughts with me in the reviews, and keep them coming! :)

* * *

**An Ultimatum to Make**

It was the afternoon of November second, 1983.

Not the Doctor's favorite year.

It was Lawrence, Kansas.

Not the Doctor's favorite place in 1983.

He knew that only hours later, inside the house that stood in front of him as he leaned heavily against the TARDIS, his blood would be used to hurt Samuel Winchester. And that was more painful than anything. It stood alongside Rose's entrapment and Donna's memory loss as one of the greatest regrets of this incarnation. His blood. His fault.

But that was not the point of coming here, he reminded himself as he straightened with effort. He wasn't here to wallow. He staggered, just briefly, righting himself with a hand on the worn wood of his most constant companion.

He saw him outside of the door, facing the entrance to the house. He knew that the form he saw him in was only a construct of his mind, based on what he knew the angel would look like twenty-five years later, but he saw him nonetheless.

The Time Lord walked up to the angel, who remained still, keeping his silent vigil. He knew the Doctor was there, the Doctor was sure, but he didn't turn or acknowledge him in any way, even when the Doctor arrived at the door.

They stood there, for a moment, in silence. For the angel, it was intentional. He had nothing to say. For the Doctor, it was necessity. He found himself leaning against the door frame.

He looked down at his hand, which was exuding regenerative energy at a greater rate than previously. He didn't have long.

He looked up to see the angel gazing at his hand with a mild curiosity. "Castiel," the Doctor said.

The angel met his eyes, tilting his head to the side as he studied him. "You are not of this planet," he said.

"No," the Doctor agreed.

Castiel narrowed his eyes. "You are...Gallifreyan."

"Yes," the Doctor whispered, gathering his strength.

"I was of the belief that your kind had perished," said Castiel.

The Doctor shrugged, a mockery of carelessness. "Last one," he said. "Billions down, one to go, I suppose."

Castiel glanced back down at the Doctor's hand. "Your body is failing," he remarked.

There was no point in denying it. "I am...wrapping up my affairs before I regenerate," he said.

Castiel's curious expression was quickly stifled, and he tensed. "What business do you have here?" he asked.

Before the Doctor could respond, both of them heard a piercing shriek of laughter. The Doctor peered through the window to see a small, dark-haired child running through the living room, pursued by a young blonde woman. He felt a shock of painful recognition, looking at the boy—he had never seen any look resembling that easy happiness on that face before.

He winced as he realized that he was witnessing perhaps the last time that that expression would find its way onto Dean's face.

In less than eighteen hours, Azazel, full of the Doctor's blood, would make his way upstairs to little Samuel's nursery, kill Mary, and feed Samuel the blood that would reroute his brain, leave him vulnerable to manipulation, and lead him and his father and his brother into a life of fear and violence.

And he couldn't stop it.

"I cannot allow you to interfere in what will take place here tonight," Castiel continued. "It is...unfortunate. But it is part of the plan."

"I know," the Doctor said. He choked out a laugh. "I know so well."

Some of the tension left the angel's posture (or what the Doctor had constructed as the angel's posture), and some of the curiosity returned. "Then what?"

The Doctor turned to him, hands in his pockets. "You," he said.

The angel shifted to look at him. There was no emotion on his face, simply that careful, neutral curiosity. The Doctor wondered briefly if he ever looked that alien to his Companions. "I don't understand," Castiel replied.

The Doctor glanced back inside the house, where Dean was enthusiastically showing Samuel how to connect Legos together. "I know you've been charged with Dean's care," he said.

Castiel said nothing.

"He will need you more than he will ever be able to express," the Doctor said. "But I know your kind, Castiel. I know your...loyalty. Your obedience and your dedication to following your orders."

"Would you do otherwise, if you had orders from the source from which ours come?" Castiel asked, sounding surprised.

The Doctor hesitated, then decided to ignore the question, because he knew the answer. Of _course_ he would do otherwise. If there was an "otherwise" to do, the Doctor would always do that. "Dean and his brother are special, but you knew that," the Doctor said. "They're unpredictable. More so after tonight. You may need to be...flexible."

"Flexible." Castiel frowned.

"You haven't been to Earth in many years, I assume," the Doctor said. Castiel nodded, and the Doctor sighed. "Humans...are remarkable."

"My Father's favored creation," Castiel agreed.

The Doctor wasn't touching that. "They are remarkable. Brilliant and brave and capable of the best and worst in the universe. And they rub off on you, Castiel."

Castiel shook his head. "I don't understand," he said again.

"You won't," the Doctor said, "not until it happens. It's not a bad thing, Castiel, to become like them."

"That will not happen," Castiel said with surety.

The Doctor shrugged. "Perhaps."

Pain flared in his core, and the Doctor gripped the doorframe. Castiel put a hand on his shoulder, and then took it away quickly as though it burned him. "I cannot help you. The radiation poisoning is too far advanced."

"I know," the Doctor said through gritted teeth. "It's not—not important."

"Then what is important?"

The Doctor paused. "What is important," he echoed. "What is important, Castiel, is that you know, until you understand for yourself, that you are not the only one watching these boys."

The Doctor's construct of Castiel did not include wings, although he could always sense them, even when he could see Jimmy Novak's body. He could feel them flare when the angel was angry. He felt them flare now. "It would be unwise to threaten me, Time Lord," Castiel said, his voice low.

The Doctor shook his head, weary. "I don't threaten, Castiel," he said. "I inform. I ask. I'm asking you to think about two things. Can you do that for me?"

Castiel frowned. "I don't see how thinking about things could give me difficulty," he said.

The Doctor chuckled under his breath. "Ah, some things don't change, at least," he said, with effort. "Two things, Castiel. Thing one. That if humans are your father's favored creation, there's got to be something _to_ them, doesn't there? There's got to be something wonderful about them." He reached out to grip Castiel's shoulder, but his gesture fell short. Castiel caught him as he fell. "Find that something," the Doctor whispered.

It took a long time for the Doctor to rally his strength. Castiel was patient, but still subconsciously thought of him as a human. Humans did not go this long without speaking, when they were in conversation. The angel frowned. "You said two things," he said. "That is only one."

"Thing two," the Doctor gasped through the pain, throwing himself upright, latching onto the door frame. "Thing two. They will make you angry. So angry. They are impossible and infuriating and ungrateful. They are rude and untrusting and violent. And I swear by every deity on every planet I've ever visited, every planet I've ever saved, if you hurt them I will find you."

Castiel tilted his head. What a familiar motion. But this Castiel was not that Castiel. This Castiel had years to go before he was the Castiel who would sacrifice himself, over and over, for the sake of the humans in his care. Who would give up everything he knew and had to keep those humans safe. Who would do it silently, without thanks, because the Winchesters didn't know how. The Doctor knew _that_ Castiel would never, ever hurt the Winchesters.

That Castiel had yet to be created.

(It was just a nudge.)

"That is a threat," Castiel remarked, but the gravel in his voice belied the easy simplicity of his words.

The Doctor shook his head wearily. "It is the truth," he rasped. "I think..._very_ highly of you, Castiel, so do a dying man a favor and don't prove me wrong."

Castiel studied him in silence, and then said, "You have asked me to think about these two things. I will do so."

The Doctor nodded, and dug deep to find the strength inside of him to stand on his own. Castiel tensed slightly, as though ready to catch him if he were to fall.

"Thank you," the Doctor said. "And I'm sorry."

As the Doctor walked away, he thought that if Castiel were human, he would have asked, _sorry for what?_ and shouted the question repeatedly at the Doctor until either the Time Lord was gone or the question was answered.

Castiel was not human.

The Doctor stepped into the TARDIS, gasping for breath. _One more stop, old boy,_ he thought raggedly. _Just one_.

And then he could let go.


	3. A Favor to Ask

**_A Favor to Ask_**

Jack was so lost.

The Doctor could see it on his face. After more than a century of wandering, Jack was starting to feel the strain.

He wished he could go to him. But he didn't. Not yet. And it made Jack the man he had to be, all these years without comfort, abandoned and undying.

The Doctor didn't like to think what it had made _him_.

Jack sat in a motel room. (Motel rooms. If in his next incarnation the Doctor never had to see the people he cared about in the inside of a motel room again, he would perhaps consider believing in a higher power.) He had a book in one hand, a small amount of scotch in a glass in the other. The Doctor knew better than to worry about the alcohol; Jack was no Winchester. Not that it would matter, anyway. His liver would repair the damage.

And if Jack were to grieve, he wouldn't do it alone. He never did.

He wondered if it was just to ask anything of Jack. To give him false hope. It would be years still before Jack saw the Doctor again, and that meeting would hardly be a joyful reunion.

On the other hand, Jack was a man who needed purpose. Who needed a cause to fight for and people to protect. He'd learned that from the Doctor; one of the many injustices heaped upon him by that chance meeting during the Blitz. But perhaps this would give him something to fight for, even if just for a little while.

(Besides, the Doctor told himself, he'd already said his good-byes to Jack. He'd already done his best to do right by him. _His name is Alonzo_.)

Jack's voice whispered in his head, _What would I say if you didn't ask me?_

The Doctor startled.

_If I knew I could have helped, if something happens and I could have stopped it, what do you think that'll do to me? And you know I'll find out because you can never keep your mouth shut._

The Doctor frowned, put out. Jack-in-his-head was as snide as Jack in real life.

_We make our paths. I could have stopped fighting, if I'd wanted to. Give me the letter, Doctor. If you're going to keep away from me, at least let me do something to help you._

It wasn't Jack. The Doctor knew it wasn't Jack. It's just what Jack would say. But he still wondered, hazily, what he'd ever done to deserve people in his life who considered his letting them help him a favor.

He held the envelope, struggling. Dark blue, TARDIS blue, and thick with the papers Jack would need, all the information to guide him. If it wasn't Jack, there was no one else he could turn to. It was 1994, and Jack was the only one.

What would Jack think if he let those boys get hurt, possibly killed, because he didn't want to _bother_ him?

If he allowed a paradox to occur all for the sake of being _fair_ to Jack?

Jack would be furious.

Jack would be right.

The Doctor slipped the envelope under the door, and, with a heavy heart, returned to his TARDIS for the last time.

* * *

Jack heard a soft sound on the filthy carpet of the motel.

He didn't allow himself to hope too much that it was what he thought it was.

He gave it a moment before looking up, and seeing the blue envelope on the ground.

He almost spilled his scotch, but managed to land it on the table before he threw himself out of his chair, lurching towards the door as though afraid that the envelope would disappear before he could get to it.

It was so solid, so real, so _present_ in his hands that he almost wept.

He didn't want to open it, at first, just savored the feeling of it, the reality of it. Thought about the hands that slipped it under his door. Thought about the man who knew he was here, who _needed_ him to know something, maybe (he barely dared to hope) to _do_ something.

His finger slid under the lip of the envelope.

With trembling hands he emptied the envelope of its contents, pulling out a thick bunch of papers. Pages and pages, like a script.

_Jack_, said the thin handwriting.

Thank god.

_I am so sorry, but I need your help._

Thank _god_.

_There are two photographs attached to this letter. Find them._

Jack found them, blurry and candid, each with two boys pictured, one with an older man in the background. He studied them for a moment, drawn in by the bizarre, haunting _adultness_ of the boys' expressions, before returning to the letter.

_These boys will be murdered on May second, 1994, if you don't save them. They can't know about me. But if they die, the paradox it creates could wipe out half the universe, and certainly all of Earth._

_These boys need you._

The handwriting changed slightly, looked more hesitant.

_I need you_.

(Thank god.)

Jack read an address, a city, and travel instructions.

It was April twenty-eighth, 1994.

He had two days to get to America in time.

Captain Jack Harkness packed his bags.

* * *

Author's Note: Two things.

Thing one: Ten has tied up his loose ends with the Winchesters, but that doesn't mean at all that there won't be more adventures with him. If nothing else we have to get to all the confusing, timey-wimey feelings everybody's going to have towards the Doctor post-this story and post-"What Power", because that's going to be fun to write.

Thing two: But before we get to explore the rest of Ten's timeline with the Winchesters, we have some Captain Jack craziness coming up next! It might take a couple of days to start posting chapters, but I think it's going to be a fun story. Stay tuned!


End file.
